Microbiology List: FW: MILK agar?

marty marty38 at aol.com
Sat Feb 24 16:11:33 EST 2001


I'd also recommend trying to autoclave the skim milk solution at only 
115 C or even dropping the time to 12 minutes. I prepare skim milk 
solutions regularly for use as a cryopreservative. 121 C for 15 minutes 
is too much heat for the skim milk.

Marty Gross
Media Preparation
American Type Culture Collection



In article <A138892BF68DD111B45800600842D1E40110B9 at PERRITTLAB01>, 
Rfriedel at perrittlab.com (Robert Friedel) wrote:

> 1) Skim Milk Agar- pH 7.0 +/- 0.1
> 
> Agar 15.0 grams
> Pancreatic Digest of Casein 5.0 grams
> Yeast Extract 2.5 grams
> Glucose 1.0 grams
> Add components except Skim Milk Solution. 
> 
> 2) Skim Milk Solution 100 milliliters
> Add skim milk solids to purified water and bring volume to 100 
> milliliters.
> Mix and autoclave for 15 minutes at 121C/15 psi.  Cool to 45-50C.
> 
> 3) Aseptically add 100 milliliters of cooled Skim Milk Solution to (1).
> 
> Atlas, R. M. 
> Handbook of Microbiological Media, 1993
> 
> Bob Friedel
> Quality Assurance Manager
> Perritt Laboratories, Inc. 
> rfriedel at perrittlab.com
> 
> -----Original Message-----
> From: Hochberg, Alan M [mailto:Hochbeam at Qualicon.email.dupont.com]
> Sent: Thursday, February 22, 2001 7:52 AM
> To: micro-list at qualicon.com
> Subject: Microbiology List: FW: MILK agar?
> 
> 
> From:	J.Rowlands [mailto:oss004 at bangor.ac.uk]
> <mailto:[mailto:oss004 at bangor.ac.uk]> 
> Sent:	Thursday, February 22, 2001 6:43 AM
> To:	microbio at hgmp.mrc.ac.uk <mailto:microbio at hgmp.mrc.ac.uk> 
> Subject:	MILK agar?
> 
> G'day all,
> 
> I've a student trying to get to grips with milk agar for a protease test.
> It's a long time since I did this!  References suggest autoclaving
> milk-powder solution, but this seems dooomed to failure with heat
> denaturation.  
> Anyone currently engaged successfully in milk agar that can give advice 
> will
> become our lab hero for the week!
> 				Many thanks,
> John Rowlands,
> University of Wales, Bangor.






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